1. Field of the Invention
The present invention relates to an external fixation device, which is designed for the setting and corrective treatment of bone fractures. More particularly, the invention is directed to the provision of an external orthopaedic wrist fixation device for the setting and corrective treatment of bone fractures which may be encountered in the distal radial portion of the forearm of a patient, through the utilization of novel cross pin arrangements extending through the site of the fracture for fracture fixation and with the absence of the risks and discomfort of encountered Ligamentotaxis.
Basically, fractures which are encountered in the bones of patients due to various causes are treated and corrected through essentially the selective application of three different generally known methods or concepts. A first one of these concepts or methods is directed to maintaining the fracture site in fixed position through the intermediary of external bandaging, for instance, which may be in the form of plaster casts or similar immobilizing structures encompassing the fracture site.
A second method, which is employed in the setting and correcting of bone fractures by immobilizing the fracture site, resides in the provision of internal fastening devices or splints, which are surgically inserted at the fracture site into the limb of the patient and enclosed therewithin. These internal fastening devices may incorporate rails equipped with screws, rods, nails, pins, wires, or screws per se and plate structures. These devices generally necessitate the implementation of extensive invasive surgical procedures, which may readily lead to infections and are difficult to treat without corrective follow-up surgery, which is required for removing such internal devices subsequent to the healing of the fracture site.
A third method, which is also widely employed in the treatment of fractures, relates to the deployment of an external fixation device or splint having pins mounted thereon, with the pins passing through the skin and soft internal tissues of the patient so as to extend into the bone on opposite sides of a fracture site, and with an external connection member mounting the pins for fixation in their predetermined positions in the bone until healing is completed over a period of weeks or other extended times.
All of these above-mentioned orthopaedic treatment devices and methods are intended to provide for the correction of bone fractures and to propagate healing at an intended minimal degree of discomfort and pain to the patient, while engaged in attempts of minimizing the risks of infection or having to conduct or implement further follow-up surgical procedures which may be deleterious to the health and comfort of the patient.
With regard to the widely employed external fixation devices for the setting and correction of bone fractures that have been proposed and which are currently employed, many diverse types of devices are designed to be utilized in connection with specific kinds of fractures. Although such devices are generally satisfactory in accomplishing their intended purpose, in effect, in effectuating the healing of the fractures, many of these are subject to structural and physical limitations when employed with patients in that they often are quite heavy, and resultingly present a high degree of discomfort to the patient, particularly children or adolescents, during the prolonged periods of use thereof. Alternatively, the devices are of the type which inhibits the mobility at various locations at which the fractures are encountered, such as the knee or the wrist, which may have long lasting or permanent adverse effects on the recovery and regaining of the full use of such limbs or joints.
For instance, a common type of bone fracture which is frequently encountered when patients trip or fall, is a result of the patient trying to regain his or her balance by extending the arms, with the wrists ordinarily taking the major shock or impact during the fall. This leads to open and/or unstable fractures of the distal radius of the forearm, inasmuch as that part of the forearm is subject to the heaviest impact or force when striking against a hard surface or structure.
Heretofore, in the employment of orthopaedic external wrist fixation devices incorporating bone-penetrating pins or wires utilized to immobilize a forearm fracture site while retaining the fractured bone sections in a contacting position, the distal radius portion of the forearm is frequently anchored by pins of the devices to the hand or flexural parts of the wrists, such as the fingers, whereas other pins are anchored to the proximal or downstream site of the forearm fracture. This may cause the hand to be immobilized or limited in its movement, although the pins at the distal or upstream site of the fracture may have their outer ends connected to swivable or movable components of the external fixation device. Nevertheless, this still poses a hindrance to the unencumbered movement of the hand of the patient and may be of a type which does not facilitate an appropriate or rapid healing of the fracture site, and may be a cause of Ligamentotaxis.
Other currently employed bone fracture treating devices comprising external fixators, wherein pins are adapted to be extended through the skin and soft tissue of the patient into the bone in both upstream and downstream locations relative to the fracture site, are at times quite heavy in their constructions and may cause a compression in the fracture site, while, upon occasion, not being able to rigidly clamp together the fractured bone sections in an appropriately aligned and immobilized manner which would propagate the rapid healing thereof. That represents a problem, which in particular is encountered in fractures of the distal radius of the forearm of a patient, in that only a minimal amount of space is available for setting the fractured bone segments in a manner without adversely affecting the mobility of the patient's hand and fingers, while concurrently ensuring the provision of a lightweight structure, which is conducive towards affording a high degree of comfort to the patient during the normally prolonged period of healing necessary for the correction and treatment of such fractures, especially those which are encountered by young and tender patients, such as children and adolescents.
2. Discussion of the Prior Art
Thus, Faccioli, et al., U.S. Pat. No. 5,728,096, discloses an external trochanter splint in which a plurality of pins are adapted to extend into the bone of the patient at the upstream and downstream locations of the fracture. However, this particular structure is primarily designed to provide mobility to the knee of a patient and is of an extremely complicated and heavy arrangement in an attempt of ensuring mobility of the knee. The splint device would not be particularly suitable for providing fixing of the fracture at the distal radius of a forearm of a patient, due to its heavy weight and bulky complexity, while avoiding immobilizing the hand of the patients, which also considerably enhances or increases the costs thereof, and raises the risk of Ligamentotaxis.
Faccioli, et al, U.S. Pat. No. 5,951,556, discloses a compact external fixation device, wherein pins extending from a swivable external clamping unit are adapted to extend into the forearm bone of the patient downstream of a fracture, and further pins are adapted to extend into the bones of the patient's hand. Although, this fixation device is particularly intended to be generally employed for treating bone fractures of children; as can be ascertained, in this instance the complexity of the device of this patent and the weight thereof is such as to render it rather cumbersome and expensive, while adding to the discomfort of the patient, particularly a young child who may be unwilling or unable to support the weight of such a fixation device in a comfortable manner over a protracted period of time, as may be required for the fracture healing process.
Day, U.S. Pat. No. 4,135,505, also discloses a device utilizing pins or screws mounted on a splint-like bar, which pins are adapted to be introduced into the bone of a patient both upstream and downstream of a fracture site, and which includes adjustable means for maintaining the fracture in a correct treatable position. This is a relatively complex orthopedic fixation apparatus, which may not be able to be readily employed in a restricted spatial area, such as that containing the fracture site in a distal radial portion of a forearm, particularly that of a child or infant.
Similarly, Mraz, U.S. Pat. No. 2,333,033, includes a structure for orienting bone fixing pins in angular positions upstream and downstream pins of a fracture site, wherein the pins are mounted on a bar comprising a complicated gear mechanism for adjusting and fixing the axial positioning of the bone segments on the opposite sides of the fracture. This results in a heavy and cumbersome structure, which cannot be easily employed in the fixation of bone segments which are subjected to a distal radial fracture in the forearm of a patient.
The foregoing is also applicable to Siebrandt, U.S. Pat. No. 2,435,850, which includes a plurality of screws extending from a splint, and which are anchored in the bone of a patient on opposite locations of a fracture site, and which also would not be practical or applicable to the correction of a fracture in the distal radius of a forearm of a patient, while maintaining the mobility of the patient's hand.
Similarly, Goudfrooy, U.S. Pat. No. 4,299,212 discloses an external fracture immobilization splint having a plurality of mutually angled and intersecting pins adapted to be inserted into the bone of a patient, and with the pins being mounted on two axially movable heads located on the splint so as to be adjustably located on the upstream and downstream sides of a fracture site. This is a relatively complicated and heavy structure which is adapted to provide for sliding adjustable movement along a rod of the splint, and is not readily applicable for use in the setting of fractures in the distal radius of a patient's forearm, in which a minimal amount of space and weight is required in the stabilization of open and/or unstable fractures of the distal radius.
Agee, et al., U.S. Pat. No. 4,922,896, also discloses a colles' fracture split, which is adapted to employ pins extending into the bone on one side of a bone fracture and a pivotal element mounted on a bar for insertion into the bone of a patient on the opposite side, wherein a metacarpal bar can be rotated about an axis parallel to the longitudinal axis of the element, so as to provide limited motion to the hand of a patient.
Other patents of varying degrees of interest, which are directed to the treatment of bone fractures, are Helland, U.S. Pat. No. 4,488,542; Evans, et al., U.S. Pat. No. 4,271,832; and Weisenbach, U.S. Pat. No. 1,789,060.
Although all of these foregoing and numerous other orthopaedic external fixation devices are adapted to provide for the immobilization and healing correction of fractures in patient's bones, none of these are capable of providing a lightweight external wrist fixator device in accordance with the present invention.